1. Field of the Invention
The present invention relates to a distance measuring device by which a three-dimensional shape of a measurement subject, which is to be measured, is captured by a time-of-flight measurement.
2. Description of the Related Art
Conventionally, a distance measuring device that detects distance from the device to a measurement subject for each pixel of an imaging device is known in xe2x80x9cMeasurement Science and Technologyxe2x80x9d (S. Christie et al., vol. 6, p.1301-1308, 1995) or International Publication No. WO97/01111. The above distance measuring device radiates pulse modulated laser light beams to the measurement subject and receives the reflected light beams on the imaging device, a two-dimensional CCD sensor, and the received light beams are converted to electric signals at each of the photoelectric conversion elements of the CCD. The shuttering operation of the distance measuring device is so controlled as to correlate electric signals, which are detected at each of the photo-diodes, with distance information from the device to the measurement subject. From the electric signals, the distance information from the device to the measurement subject is detected at each pixel of the CCD, and the three-dimensional distance information that indicates the topography of the measurement subject is obtained. However, the three-dimensional distance information of the measurement subject is comprised only of relative distances from the device and the ground position of the measurement subject is not obtainable.
An object of the present invention is to provide a ground positioning system, which detects the ground position of a measurement subject, applied in the distance measuring device that detects the distance from the device to a measurement subject for each pixel of the captured image of the measurement subject.
According to the present invention, there is provided a ground positioning system applied in a distance measuring device that detects the distance from the distance measuring device to a measurement subject for each pixel of the captured image of the measurement subject. The ground positioning system comprises a ground position detecting processor, an azimuth detecting processor and a subject position calculating processor.
The ground position detecting processor detects the ground positioning coordinates of the distance measuring device. The azimuth detecting processor detects the direction of the distance measuring device. The subject position calculating processor calculates the ground positioning coordinates of a subject that correspond to a certain pixel of captured image using the distance value, the ground positioning coordinates and the direction of the distance measuring device.
Preferably, the ground positioning system further comprises an image indicating processor, an input processor, a map information search processor and a superimpose processor. The image indicating processor displays the captured image on a screen. The input processor is for selecting at least one pixel of the image, which is indicated on the screen by the image indicating processor. The map information search processor searches a piece of map information that corresponds to the ground positioning coordinates of a pixel which is selected by the input processor. The superimpose processor superimposes the piece of map information, which is searched by the map information search processor, in proximity to the selected pixel.
In a preferable example of the ground positioning system, the input processor may comprise a touch screen, the map information may comprise names of facilities that exist at locations indicated with the ground positioning coordinates and the ground positioning coordinates may comprise longitude and latitude.
Further, the preferred example of the ground positioning system comprises an inclination detecting processor that detects the inclination angle of the distance measuring device. The position calculating processor calculates the ground positioning coordinates of the subject. The coordinates corresponds to the distance value, that coincides with a certain pixel of the captured image, and the ground positioning coordinates, the direction and inclination angle of the distance measuring device.
The ground position detecting processor comprises a GPS (Global Positioning System) receiver so as to detect the ground positioning coordinates.